How to Bypass 4 Wire Seat Safety Switch on Lawn Mower

Lawnmowers have safety features that avoid accidents. Bypassing the safety features of your lawnmower may be necessary during repairs.

To bypass a 4-wire seat safety switch, you must first gather the necessary materials and equipment, then disconnect the battery and spark plug connections, lift the seat and locate the switch, then disable it. Put the mower back together and turn it on.

This article provides information about how the safety switch works, what could go wrong, how to test and bypass it. Also, the step-by-step guide on how to Bypass 4 wire seat safety switch will be discussed.

How to Bypass 4 Wire Seat Safety Switch on Lawn Mower

How 4 Wire Seat Safety Switch Works?

A four-pronged connector with a button on top represents the seat’s safety switch. The button features two sets of contacts at its base.

Two of the blades are connected by one set, and the other two are connected by another set. The first set is grounded, while the second is connected to the engine. If you sit in the seat and press the button, power will flow from the battery to the engine, but if you get up, the connection will be severed and the engine will shut off.

The seat safety switch has 4 wires. Depending on the model of the mower the color of the wires varies.

4 Wire Seat Safety Switch

The Seat Safety Switch: What Could Go Wrong?

The wires that run down the base of safety switches are susceptible to corrosion, breakage, and bending. A faulty switch cannot complete the circuit required for the engine to run.

The circuit can be “jumped” by removing the switch, and the mower will start and run whether the operator is seated or not. Nonetheless, manufacturers highly discourage bypassing the inexpensive and easily replaceable switch.

Related Post: How to Bypass 2 Wire Seat Safety Switch?

How Do You Test a Lawn Mower Seat Safety Switch?

To test your 4-wire seat safety switch, perform the procedures below:

  1. Take a seat in the mower’s driver’s seat. To lock the parking brake, depress the lever to the right of the steering wheel.
  2. To disable the blades by pushing down the PTO switch on the right side of the dash
  3. For a cold start, raise the throttle lever to roughly half throttle. If the lawnmower was recently used and is heated, adjust the throttle lever to the slow setting.
  4. To activate the choke, lift the lever located on the left side of the dashboard. To start the mower, insert the key into the ignition and turn it. If you want to stop the engine from running, you should do it by releasing the key and then moving the choke lever down.
  5. To increase the engine’s maximum speed, go to the left side of the dashboard and pull up on the throttle lever. To unlock the right-side park brake, simply pull the lock outward. Release the brakes by pressing the lever to the right of the engine. With this, the brake is released.
  6. To activate the blade rotation, the PTO switch is located on the right side of the dashboard and must be pushed up. Get up out of your chair. If the seat safety switch is functioning properly, the engine and blade motion will halt. The safety interlock switch located beneath the seat is broken if either of these two actions continues.

How Can You Bypass 4 Wire Seat Safety Switch? (4 Steps Explained)

There are several ways to bypass a 4-wire seat safety switch.

Disconnecting the two wires that are linked to the switch is one option. This will allow you to connect the wires directly without using the switch.

Instead, a jumper wire can be used to bypass the switch. Jumper wires are easy to install; just join one end to a switch’s wire and the other end to the other wire. Even if the switch is in the “off” position, this will still cause the circuit to be completed and allow current to flow through.

Here is a step-by-step guide on bypassing a lawn mower’s seat safety switch:

Step 1: Disconnect the Battery and Spark Plug Cables

Before beginning the adjustments, it is strongly advised that you take the necessary precautions.

  • Pull the wires off the spark plugs first.
  • Remove the key from the ignition.
  • The battery should also be disconnected.
  • Taking the cord off the battery’s negative terminal will do this.

Following these instructions will protect you from potential electrical harm.

Step 2: Lift the Seat in to Find the Switch

After disconnecting the connections, you can proceed to the following step.

  • You will find the emergency button beneath your seat. With a wrench, you can loosen the bolt holding the seat to the mower’s frame. Typically, the seat may be lifted off of a mower without needing to undo any bolts.
  • The safety switch is located under the seat and must be accessed with the seat raised. The cable may run from under the seat to the center of the seat. The switch’s location is electrically connected by this cable. Take apart the connector before you start making changes.

Step 3: Disable the Switch

The switch can be disabled by removing the connector and insulating its contacts. Here are the measures you should take:

  • In order to access the connector and disconnect it, you’ll need to slide the seat cover upwards. To get to the switch and its connector, loosen the nuts holding the metal cover to the seat in place and slide it upwards.
  • You can pry the plug out of its socket with a screwdriver. It’s possible there are now three or four prongs protruding from the connecting plug. Such spring like action is provided by these pins.
  •  The pins in the safety switch close when a human sits on the seat, allowing electricity to flow. This link is what keeps the motor running. When the load is taken off, the pins no longer touch, and the circuit is broken.

The primary objective for deactivating the switch is to prevent the pins from making contact.

  • You can achieve this by inserting toothpicks into their ends. Instead, you can slip thick cardboard (or a used credit card) between the pins. However, using nose pliers to take the pins out of the connector case is the most effective and non-destructive method. When you wish to reactivate the switch, you can reintroduce them.

Step 4: Re-assemble and Start the Mower

  • With the pins removed, the circuit bypasses the safety switch. Return the mower seat to its original position.
  • Join the battery cables and spark plug together. Restart your riding mower by seating down on the seat.
  • Now, you can leave your seat without your engine shutting off. The seat safety switch has now been eliminated from consideration.

Read also: The Guide on PTO Switch Wiring Diagram

How Many Safety Switches Are On A Lawnmower?

In general, a lawnmower will have between three and four different kinds of safety switches to ensure protection. Among these are-

  • Seat safety switch
  • Mower deck safety switch
  • PTO (Power Takeoff) Switch.

What Is the Function of A Two-Wire Safety Switch In A Seat?

The emergency button on the seat belt appears like a four-pronged plug. There are two sets of contacts inside the button’s base. Two of the blades are connected by one set, and the other two are connected by another set. The first pair is connected to the motor, and the second pair is grounded.

Final Words

The safety switch is an important safety feature that prevents accidents when operating the lawnmower. It is recommended that safety switches should not be bypassed, but, if necessary, there are several ways to do so.

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